Outdoor umbrellas are employed to shield people from the sun, wind, rain, and other elements of nature. As such, they are intentionally designed to withstand these elements. Nevertheless, damage to the framework of an umbrella can and does occur for many reasons, particularly to umbrellas in geographical areas of severe and unexpected weather, as well as umbrellas which have been improperly installed. Many prior art umbrellas suffer the disadvantages of not being able to withstand harsh weather as well as not being capable of simple repair when damage does occur. For example, an umbrella having static wire, rigid line and an unbalanced construction at the rib and strut pivot point will wear and often break when extreme forces are applied over time. Because the static or rigid line connects a plurality of ribs and struts at the upper and lower central hubs, any compromise of this entity will mean the collapse of the entire canopy assembly. Further, once an umbrella is damaged, it is often more expensive and difficult to repair the umbrella than to have it replaced.
For umbrellas having individual pivotal connections between the upper rib and lower strut assembly, the unbalanced nature of the movement at the pivot point in relation to the upper and lower central hubs causes unnecessary wear on the pivot junction as well as to the static wire or rigid line which connects the canopy rib assembly to the central hubs. This wear is undesirable and is aggravated over time by the stresses of both man and nature.
For umbrellas having individual pivotal connections between the upper rib and lower strut assembly by means of a vertically configured bracket individually, the existing plastic brackets protrude over the top of the canopy assembly providing a point of friction between the fabric of the canopy and the rigid protrusion of the pivot bracket. This creates excessive wear on a fabric canopy and often creates holes in the fabric canopy.
Various umbrella frames are described, for example, in the following U.S. Pat. Nos.: D25,368 to Sparry; D56,043 to Weinberg et al.; U.S. Pat. No. 2,336,116 to Morando; U.S. Pat. No. 3,177,882 to Militano; U.S. Pat. No. 4,368,749 to Lindler et al.; U.S. Pat. No. 4,834,126 to Sweet, Jr.; and U.S. Pat. No. 5,715,853 to Lin. None of these umbrella frames shows the connection of a central hub with a secondary hub in a manner which allows for the quick exchange of components so as to allow the customization of the size and shape of the canopy member atop the umbrella frame.
By the present invention, there is provided a durable outdoor umbrella frame that will withstand extreme forces and that may be quickly, easily and inexpensively repaired. The present invention is also easily modified to accommodate umbrella canopies of different sizes and shapes. The present invention includes a pair of hub members having a set of slots about their radial edges for receiving a combination of hub connector joints. A matching number of ribs and struts are pivotally secured to each hub by these joints, and the struts are pivotally secured to the ribs by collar members. The hub connector joints and the collar members are easily mounted and replaced, and assist in the smooth operation of the umbrella frame. Additionally, the collar members maintain a low profile so as to avoid contacting and thereby potentially damaging a mounted canopy.
It is thus one object of the present invention to provide an umbrella frame which can be easily manipulated to allow the attachment of canopies of varying shapes and sizes.
It is another object of the present invention to provide an umbrella frame capable of withstanding extreme temperature, wind and other weather conditions.
It is a further object of the present invention to provide an umbrella frame capable of simple rotation.
It is another object of the present invention to provide an umbrella frame having easily replaceable and interchangeable parts.